In all vehicles presently manufactured and sold, such as cars, trucks or like vehicles, the control means manually actuable by the driver in order to direct his vehicle comprise a steering wheel mounted on a steering column which is mechanically coupled to the guiding wheels. In case of an accident, for example in case of a collision with a fixed obstacle or another vehicle, the driver of the vehicle may be seriously injured, even killed in being violently thrown against the steering wheel or, should the latter deform or break, against the end of the steering column which may furthermore itself be forced into the occupant space of the car towards the driver.
Likewise, a passenger having occupied a place beside the driver may be seriously injured or even killed in being violently thrown against the dashboard and/or the windshield of the vehicle.
One of the most effective measures which have been proposed and put into practice to suppress or at least attenuate this danger consists in equipping the vehicle with a safety arrangement comprising inflatable protective bags which are normally empty and folded in suitable housings and which are rapidly inflated in case of collision, such bags being arranged and dimensioned in a manner such that when they are inflated, they dampen the impact of the driver and his passenger respectively against the steering wheel and against the dashboard or windshield.
The housing intended to contain the conductor's protective bag in normal conditions, that is to say when the bag is empty and folded, is generally in the hub of the steering wheel while the protective bag for the passenger or passengers is arranged in a dashboard compartment.
There results on the one hand that such hub must have relatively substantial dimensions which may interfere with the visibility of the instruments on the dashboard and, on the other hand, that such bag cannot assume large dimensions when it is inflated, which limits its effectiveness in the case of an accident.
There likewise results that the protective bag of the driver and the protective bag of the passenger must be distinct from one another, which increases the cost of the overall safety arrangement. Such safety arrangements are described for example in patent document DE 2 123 325.
Patent document FR 2 227 979 proposes another safety arrangement of this nature. In this document, the safety arrangement comprises two systems of protective bags, respectively inflatable for the driver and for the passenger or passengers. Such bag systems are located in a folded state in a compartment located in the neighbourhood of the ceiling of the vehicle occupant space. Each bag system comprises a bag section for retaining the trunk and a bag section forming a lateral curtain, such two sections being secured to the ceiling. Each of such sections is connected to a gas source, separated from the bags by inflatable tubes. The bag section for retaining the trunk is intended to be interposed between the occupants in the front of the vehicle and the steering wheel or dashboard, and the bag section forming a lateral curtain is intended to be interposed between an occupant and a lateral wall of the vehicle. Such an arrangement nevertheless still presents numerous drawbacks.
The first disadvantage resides in the fact that the bag systems for the driver and the passenger or passengers are independent, which brings about a substantial volume and weight to be housed in the compartment and necessitates separate gas sources. The cost of such an arrangement is thus elevated. This furthermore constitutes a non-negligible encumberment at the vehicle ceiling which, in order not to hamper the vehicle occupants, necessitates an increase in the height of the vehicle.
Additionally, the fact that the bags are positioned and inflated from the ceiling of the occupant space requires the occupants to be correctly settled into the bottom of their seat in order that the bags be effective at the moment of inflation. Effectively, if one of the occupants is slightly forwardly inclined or is not completely settled into the bottom of his seat at the instant when the accident occurs and when the bags are inflated, these latter, coupled with the deceleration accompanying the accident, are going in the first place to throw the head of said occupant towards the steering wheel or the dashboard. One easily understands thus that in this configuration the arrangement is not only ineffective, but also dangerous.
Another difficulty consists in that the gas source is widely separated from the different sections of the bag and that it is coupled to such latter through conduits in the form of tubes of relatively small cross-sections so that the distance to be travelled by the gas is increased and the speed of inflation diminished. Furthermore, without specific dimensioning of the cross-section of the tubes, the gas speed is limited to the speed of sound.
The invention thus has as main purpose to overcome these drawbacks of the above-mentioned prior art in furnishing an automotive vehicle provided with a safety arrangement having inflatable protective bags, the effectiveness of which is improved and the cost considerably diminished.